The present invention relates to a connecting rod for a reciprocating piston of an internal combustion engine, and more particularly to an improved lubrication system for the crankpin bearing of such a connecting rod.
Connecting rods typically have two-piece crankpin bearings for connecting the lower end of the rod to a crankpin of a crankshaft. The two-piece assembly comprises an arcuate-shaped bearing portion integrally formed on the lower end of the rod, and a cap member which is assembled to the bearing portion by means of a pair of cap screws.
Lubrication must be provided between the relatively moving crankpin and crankpin bearing parts, and has in the past been provided by bores extending radially through the crankpin bearing having an inlet located at the exterior surface of the crankpin bearing and an outlet communicating with the crankpin bearing hole. The object of these lubrication bores is to communicate a sufficient amount of oil to the interior of the crankpin bearing during operation, and in particular during startup of an engine to communicate the oil as quickly as possible to the interior of the bearing.